XP1541 Cable

Project: Fast 1541 <-> PC transfer cable (needs X1541 cable)
Target : 1541, 1570/71
Time   : 30 min.
Cost   : <10 US$
Use    : Speedup for transfers between PC and C-64 with
         the X1541 cable.

Summary

You can't solder?

• X1541 Shop [DM 12 / $7.10 + shipping] - sells all X1541 variants!

Details

Note that for both parallel ports, you need the correct mode:

• port for X1541 cable: SPP or PS/2 (bi-directional) mode
• port for XP1541 cable: ECP/EPP mode

An important note: NEVER connect the floppy drive to your PC and a C64 and have both switched on simultaneously! I highly recommend that you use a separate floppy drive exclusively for data transfers with the PC.

Ingredients

• 1 x 9-core ribbon cable, maximum length 1.50 m. Don't make it longer as needed, try to keep it under 1 m!
• 1 x DB-25 connector (male) with plug cover (the one which is on the PC side of your printer cable)
• 1 x 40-pin high precision IC socket.

Instructions

Note: When soldering the wires to the IC socket, solder only the tip of the wire to the base of the pins (the end near the plastic), so that the socket can still be plugged in and sits firmly.
1. Read Joe Forster's 'The X1541 Interfaces' first!
2. Solder one end of the wires to pins 1 to 9 of the IC socket. Note that the picture below shows the BOTTOM of the IC socket, pins pointing towards you, notch on top.
3. Now solder the wires from pins 2 to 9 of the IC socket to pins 2 to 9 of the DB25 connector.
4. Solder the wire at pin 1 of the IC socket to any one of pins 18 to 25 of the DB25 connector.
5. At last, you should interconnect pins 18 to 25 of the DB25 connector as shown below.

   
   (Click here for ASCII version)

6. Carefully verify the connections, if you connected the wrong lines, you could easily fry your VIA!
7. Put the IC socket between the socket for VIA #1 and the VIA itself (in the 1541). If the VIA isn't socketed - bad luck, you have to unsolder it first.
8. Plug the other end of the cable into a parallel port of your PC which must be in ECP/EPP mode. Don't forget to keep the X1541 cable plugged in, too - the XP1541 cable doesn't work without it!
9. When both the X1541 and XP1541 cables are plugged in, switch on the PC and the 1541 and configure Star Commander for the right parallel ports (LPT1, LPT2 or LPT3), this is done by executing SCSETUP.EXE. You should also configure them to use the slowest (most secure) transfer speed first, if possible.
10. Insert a formatted disk into the 1541 and try to access it: hit [Alt]-[F1] and then 8 (or 9 if your drive's device address is 9), the Star Commander should now display the disk's directory.

    If the program cannot access the drive, adjust the delay value; see SC.TXT (or press F1 while in the appropriate dialog box in Star Commander).

11. Switch off both 1541 and PC, disconnect the cable, and reassemble the floppy drive. Lastly, assemble the the DB-25 connector.

Possible failures

• Soldered wires to wrong pins on one or both of the connectors. The figure above depicts the plug from the SOLDER side and the socket from the MALE side, respectively.
• Printer ports are in wrong mode, configure them as follows:
  • port for X1541 cable: SPP or PS/2 (bi-directional) mode
  • port for XP1541 cable: ECP/EPP mode
• Cable is too long -> shorten cable (Don't use cables longer than 1.5 m!)

Site copyright © 1997 by Marc-Jano Knopp